Table 1 Redox potentials of commonly used oxidants indicating their reactivity

Sulfate radical (SO^−∙₄ )

Acidic to neutral

2.5–3.1^a

Hydroxyl radical (∙OH)

Acidic

2.7^a

Neutral to alkaline

1.8^a

Ferrate ([FeO₄]²⁻)

Acidic

2.2^b

Alkaline

0.7^b

Ozone (O₃)

Acidic

2.1^a

Alkaline

1.2^a

Peroxydisulfate (S₂O₈²⁻)

Acidic

2.0^a

Hydrogen peroxide (H₂O₂)

Acidic

1.8^a

Alkaline

0.9^a

Peroxymonosulfate (HSO₅⁻ or SO₅²⁻, pK_a = 9.4^c)

Acidic

1.8^a

Hydroperoxy radical (HO₂∙)

–

1.7^d

Permanganate (MnO₄⁻)

Acidic

1.7^a

Alkaline

0.6^a

Hypochlorous acid (HOCl)

–

1.5^c

Chlorine (Cl₂)

–

1.4^d

Chlorine dioxide (ClO₂)

–

1.3^d

Peroxymonosulfate radical (SO₅⁻∙)

Neutral

1.1^c

Sulfite radical (SO₃⁻∙)

Neutral

0.6^c